What is the required size of a vent pipe for a vertical stack serving 10 fixtures?

In plumbing systems, the size of the vent pipe is critical to ensuring that the system functions properly by allowing for the equalization of pressure and the release of gases. According to plumbing codes, the required size of a vent pipe is determined based on the number of fixtures being served.

For a vertical stack serving a total of 10 fixtures, the plumbing code specifies that the vent must be adequately sized to handle the airflow required for venting. A 2-inch vent pipe is generally adequate for venting purposes when serving up to 10 fixtures. This size allows for sufficient airflow to balance the pressure changes caused by the drainage of wastewater, preventing issues such as siphoning and ensuring that traps retain their water seal.

Larger vent pipes, such as 3 inches or 4 inches, are typically required for larger numbers of fixtures or specific applications but are not necessary for serving just 10 fixtures. Conversely, a 1-inch vent would be insufficient, as it would not provide enough ventilation, leading to potential operational issues within the plumbing system. Thus, the optimal size in this scenario is indeed a 2-inch vent pipe.